Can a person weighing 60 kg lift a 650 N load with a fixed block?

The fixed block does not give a gain in strength, it only changes the direction of the force applied to the load. A person weighing 60 kg can act on a block with a force equal to his weight:

P = mg = 60 kg * 10 m / s ^ 2 = 600 N.

A block is an equal-arm lever, with a shoulder equal to the radius of the block. A force of 650 N will be applied to one side, and 600 N to the other. The moment of force from the load side of 650 N will be greater, therefore the block will not rotate towards the person and he will not be able to lift the load.